Electrostatic Interactions between Acid-/Base-Containing Polymer Nanoparticles and Proteins: Impact of Polymerization pH

2020 ◽  
Vol 3 (6) ◽  
pp. 3827-3834 ◽  
Author(s):  
Ryutaro Honda ◽  
Tomohiro Gyobu ◽  
Hideto Shimahara ◽  
Yoshiko Miura ◽  
Yu Hoshino
Keyword(s):  
Electrostatic Interactions ◽  
Polymer Nanoparticles ◽  
Acid Base

A potentiometric study of the effects of molecular complexing on acid–base equilibria

1976 ◽  
Vol 54 (13) ◽  
pp. 2141-2153 ◽  
Author(s):  
A. K. Colter ◽  
D. Buben
Keyword(s):  
Electrostatic Interactions ◽  
Potentiometric Method ◽  
Acidity Constant ◽  
Complexation Constants ◽  
Acid Base ◽  
Acid Complex ◽  
Molecular Complexation ◽  
Opposing Effects ◽  
Conjugate Base ◽  
Sufficient Precision

The effect of molecular complexing on several acid–base equilibria involving organic π donor acids has been studied by a potentiometric method. The method leads to complexation constants for the acceptor with the donor acid and its conjugate base. In several cases the two association constants can be determined with sufficient precision to obtain an estimate of the acidity constant for the 1:1 acceptor–donor acid complex. In all situations where charge-transfer and electrostatic interactions are expected to have opposing effects on the acidity, electrostatic effects dominate. The range of the validity and usefulness of the potentiometric method in studies of molecular complexation equilibria is discussed, together with the results obtained in this work.

Novel Colloidal Assembly Methods for the Preparation of Core-Shell Composite Materials

2000 ◽  
Vol 636 ◽  
Author(s):  
Michael S. Fleming ◽  
Tarun K. Mandal ◽  
David R. Walt
Keyword(s):  
Electron Microscopy ◽  
Electrostatic Interactions ◽  
Physical Adsorption ◽  
Polymer Nanoparticles ◽  
Biological Interactions ◽  
Specific Chemical ◽  
Capillary Action ◽  
Colloidal Assembly ◽  
Transmission Electron ◽  
Shell Composite

AbstractColloidal assembly is a process by which particles ranging in size from nanometers to micrometers are organized into structures by mixing two or more particle types. Assembly is controlled by either specific or non-specific interactions between particles. Examples include chemical bonding, biological interactions, electrostatic interactions, capillary action and physical adsorption. The assembly process is performed such that smaller particles assemble around larger ones. In this paper, we report on colloidal assembly of polymer nanoparticles (50-200 nm diameter) onto silica particles (3-5 μm diameter) using specific chemical interactions (i.e. aminealdehyde). Annealing the assembled composites at temperatures above the glass transition (Tg) of the polymer nanospheres allows polymer to flow and uniformly coat the microsphere surfaces. Polystyrene and poly(methyl methacrylate) nanospheres were used to produce such materials. Shell composites were created by mixing both nanosphere types prior to assembly/annealing. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the materials presented herein.

On the Role of Electrostatic Interactions in Stabilization of Oxidized Nucleic Acid Base Complexes

2009 ◽  
Author(s):  
Ż. Czyżnikowska ◽  
R. Zaleśny ◽  
M. G. Papadopoulos ◽  
George Maroulis ◽  
Theodore E. Simos
Keyword(s):  
Nucleic Acid ◽  
Electrostatic Interactions ◽  
Acid Base ◽  
Nucleic Acid Base

On the Role of Electrostatic Interactions in Stabilization of Oxidized Nucleic Acid Base Complexes

2009 ◽  
Author(s):  
Ż. Czyżnikowska ◽  
R. Zaleśny ◽  
M. G. Papadopoulos ◽  
George Maroulis ◽  
Theodore E. Simos
Keyword(s):  
Nucleic Acid ◽  
Electrostatic Interactions ◽  
Acid Base ◽  
Nucleic Acid Base

Template mediated crystal engineering

1994 ◽  
Vol 52 ◽  
pp. 480-481
Author(s):  
Brigid R. Heywood ◽  
S. Champ
Keyword(s):  
Crystal Engineering ◽  
Electrostatic Interactions ◽  
Alkyl Chain ◽  
Crystallographic Axis ◽  
Two Dimensional ◽  
Engineering Process ◽  
Solution Interface ◽  
Extensive Program ◽  
Geometric Homology ◽  
Long Alkyl Chain

Recent work on the crystallisation of inorganic crystals under compressed monomolecular surfactant films has shown that two dimensional templates can be used to promote the oriented nucleation of solids. When a suitable long alkyl chain surfactant is cast on the crystallisation media a monodispersied population of crystals forms exclusively at the monolayer/solution interface. Each crystal is aligned with a specific crystallographic axis perpendicular to the plane of the monolayer suggesting that nucleation is facilitated by recognition events between the nascent inorganic solid and the organic template.For example, monolayers of the long alkyl chain surfactant, stearic acid will promote the oriented nucleation of the calcium carbonate polymorph, calcite, on the (100) face, whereas compressed monolayers of n-eicosyl sulphate will induce calcite nucleation on the (001) face, (Figure 1 & 2). An extensive program of research has confirmed the general principle that molecular recognition events at the interface (including electrostatic interactions, geometric homology, stereochemical complementarity) can be used to promote the crystal engineering process.

Higher Dietary Acidity is Associated with Lower Bone Mineral Density in Postmenopausal Iranian Women, Independent of Dietary Calcium Intake

2014 ◽  
Vol 84 (3-4) ◽  
pp. 0206-0217 ◽  
Author(s):  
Seyedeh-Elaheh Shariati-Bafghi ◽  
Elaheh Nosrat-Mirshekarlou ◽  
Mohsen Karamati ◽  
Bahram Rashidkhani
Keyword(s):  
Calcium Intake ◽  
Dietary Calcium ◽  
Dietary Calcium Intake ◽  
Dietary Intakes ◽  
Iranian Women ◽  
Acid Base Balance ◽  
Mineral Density ◽  
Acid Base ◽  
Base Balance ◽  
Dietary Acid

Findings of studies on the link between dietary acid-base balance and bone mass are relatively mixed. We examined the association between dietary acid-base balance and bone mineral density (BMD) in a sample of Iranian women, hypothesizing that a higher dietary acidity would be inversely associated with BMD, even when dietary calcium intake is adequate. In this cross-sectional study, lumbar spine and femoral neck BMDs of 151 postmenopausal women aged 50 - 85 years were measured using dual-energy x-ray absorptiometry. Dietary intakes were assessed using a validated food frequency questionnaire. Renal net acid excretion (RNAE), an estimate of acid-base balance, was then calculated indirectly from the diet using the formulae of Remer (based on dietary intakes of protein, phosphorus, potassium, and magnesium; RNAERemer) and Frassetto (based on dietary intakes of protein and potassium; RNAEFrassetto), and was energy adjusted by the residual method. After adjusting for potential confounders, multivariable adjusted means of the lumbar spine BMD of women in the highest tertiles of RNAERemer and RNAEFrassetto were significantly lower than those in the lowest tertiles (for RNAERemer: mean difference -0.084 g/cm2; P=0.007 and for RNAEFrassetto: mean difference - 0.088 g/cm2; P=0.004). Similar results were observed in a subgroup analysis of subjects with dietary calcium intake of >800 mg/day. In conclusion, a higher RNAE (i. e. more dietary acidity), which is associated with greater intake of acid-generating foods and lower intake of alkali-generating foods, may be involved in deteriorating the bone health of postmenopausal Iranian women, even in the context of adequate dietary calcium intake.

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